Preparation And Performance Research Of Biofuels Hydrorefining Catalyst

NiCl₂·6H₂O,NaH₂PO₄·2H₂O,FeCl₃·6H₂O and low-grade hydroxyapatite?HAP?were used as raw materials,the support Fe-HAP was synthesized by ion exchange method,and then the supported catalyst Ni₂P/Fe-HAP was prepared by impregnation method.The Ni₂P/Fe-HAP catalyst was characterized by means of N₂adsorption-desorption,scanning electron microscopy?SEM?,X-ray diffraction?XRD?,Fourier transform infrared spectroscopy?FT-IR?,and thermogravimetry?TG?.The selective hydrogenation of phenol to cyclohexanone was used to evaluate the catalytic activity and selectivity of Ni₂P/Fe-HAP catalysts.The conditions for the preparation of Ni₂P/Fe-HAP catalysts were investigated and optimized by single factor experiments and orthogonal experiments.Within the scope of experimental investigation,the catalytic performance of Ni₂P/Fe-HAP increased basically with the increase of the amount of nickel-phosphorus substance?A?,loading?B?,roasting temperature?C?,and Fe³⁺concentration?D?.After the trend of decreasing,the effect of Fe³⁺concentration is relatively significant.The results of orthogonal experiments showed that the optimal preparation conditions of the catalyst were 1.5nickel-phosphorus material ratio,15wt.%Loading,calcination temperature of 300?,and Fe³⁺concentration of 0.05 mol/L.At the same time,the conditions for selective hydrogenation of phenol were investigated and optimized by single-factor experiments and orthogonal experiments.Within the scope of experimental investigations,the changes in reaction temperature?E?,reaction pressure?F?,and reaction time?G?all cause changes in the catalytic activity and selectivity of Ni₂P/Fe-HAP.The influence of reaction temperature is relatively Significantly.The results of orthogonal experiments show that the optimal conditions for the selective hydrogenation of phenol are a reaction temperature of 150?,a reaction pressure of0.5 MPa,and a reaction time of 3.5 h.The experiment found that the amount of catalyst also has an impact on the catalytic performance,and the amount of catalyst must meet the principle of moderation.The experiment of selective hydrogenation of phenol to cyclohexanone was used to evaluate the catalytic performance of three catalysts,Ni₂P/HAP,Ni₂P/Fe-HAP and Ni₂P/Al₂O₃,The reaction mechanism of phenol on Fe-HAP modified support was studied.It was found that the modified support Fe-HAP can promote the rapid desorption of cyclohexanone and inhibit its excessive hydrogenation.In the selective hydrogenation of phenol,the catalytic performance of Ni₂P/Fe-HAP is better than the other two catalysts.Fe-HAP modified support and Ni₂P show a good synergy,which can significantly improve the catalytic performance of the catalyst.In addition,it was found that after being stored for 30 days under normal temperature and pressure dehumidification conditions,the stability of the catalyst was generally good.Several experiments were performed under optimal conditions.The conversion rate of Ni₂P/Fe-HAP catalyst for the selective hydrogenation of phenol was stable at more than 62%,and the selectivity to cyclohexanone was more than 73%.The catalytic performance was relatively good.